xref: /linux-6.15/include/linux/memory.h (revision d289bf7b)
1 /*
2  * include/linux/memory.h - generic memory definition
3  *
4  * This is mainly for topological representation. We define the
5  * basic "struct memory_block" here, which can be embedded in per-arch
6  * definitions or NUMA information.
7  *
8  * Basic handling of the devices is done in drivers/base/memory.c
9  * and system devices are handled in drivers/base/sys.c.
10  *
11  * Memory block are exported via sysfs in the class/memory/devices/
12  * directory.
13  *
14  */
15 #ifndef _LINUX_MEMORY_H_
16 #define _LINUX_MEMORY_H_
17 
18 #include <linux/sysdev.h>
19 #include <linux/node.h>
20 #include <linux/compiler.h>
21 #include <linux/mutex.h>
22 
23 struct memory_block {
24 	unsigned long phys_index;
25 	unsigned long state;
26 	/*
27 	 * This serializes all state change requests.  It isn't
28 	 * held during creation because the control files are
29 	 * created long after the critical areas during
30 	 * initialization.
31 	 */
32 	struct mutex state_mutex;
33 	int phys_device;		/* to which fru does this belong? */
34 	void *hw;			/* optional pointer to fw/hw data */
35 	int (*phys_callback)(struct memory_block *);
36 	struct sys_device sysdev;
37 };
38 
39 /* These states are exposed to userspace as text strings in sysfs */
40 #define	MEM_ONLINE		(1<<0) /* exposed to userspace */
41 #define	MEM_GOING_OFFLINE	(1<<1) /* exposed to userspace */
42 #define	MEM_OFFLINE		(1<<2) /* exposed to userspace */
43 #define	MEM_GOING_ONLINE	(1<<3)
44 #define	MEM_CANCEL_ONLINE	(1<<4)
45 #define	MEM_CANCEL_OFFLINE	(1<<5)
46 
47 struct memory_notify {
48 	unsigned long start_pfn;
49 	unsigned long nr_pages;
50 	int status_change_nid;
51 };
52 
53 struct notifier_block;
54 struct mem_section;
55 
56 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE
57 static inline int memory_dev_init(void)
58 {
59 	return 0;
60 }
61 static inline int register_memory_notifier(struct notifier_block *nb)
62 {
63 	return 0;
64 }
65 static inline void unregister_memory_notifier(struct notifier_block *nb)
66 {
67 }
68 static inline int memory_notify(unsigned long val, void *v)
69 {
70 	return 0;
71 }
72 #else
73 extern int register_memory_notifier(struct notifier_block *nb);
74 extern void unregister_memory_notifier(struct notifier_block *nb);
75 extern int register_new_memory(struct mem_section *);
76 extern int unregister_memory_section(struct mem_section *);
77 extern int memory_dev_init(void);
78 extern int remove_memory_block(unsigned long, struct mem_section *, int);
79 extern int memory_notify(unsigned long val, void *v);
80 #define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
81 
82 
83 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
84 
85 #ifdef CONFIG_MEMORY_HOTPLUG
86 #define hotplug_memory_notifier(fn, pri) {			\
87 	static struct notifier_block fn##_mem_nb =		\
88 		{ .notifier_call = fn, .priority = pri };	\
89 	register_memory_notifier(&fn##_mem_nb);			\
90 }
91 #else
92 #define hotplug_memory_notifier(fn, pri) do { } while (0)
93 #endif
94 
95 #endif /* _LINUX_MEMORY_H_ */
96